1. Field of the Invention
This relates to a lipstick case of the type in which the lipstick pomade may be made to advance or retract by turning the casing relative to the base. More specifically, this invention relates to a lipstick case in which the driving means for propelling the pomade up or down is in the form of a floating spirally slotted sleeve which cooperates with lugs in the base and on the pomade support.
2. Description of the Prior Art
The prior art includes the Mellette U.S. Pat. No. 2,546,195, granted Mar. 27, 1951, wherein the driving means includes three telescoping threaded sleeves. (A copy is enclosed in accordance with 35 CFR 1.97.) With the casing held from turning, the base member secured to the outer sleeve may be turned to drive up the floating intermediate sleeve which eventually drives up the inner sleeve connected to the pomade support.
An improvement on the old Mellette device is disclosed in the Wiles et al application, Ser. No. 836,853, filed Mar. 6, 1986 now abandoned, and assigned to my assignee. This improvement, which is meritorious, relates to the structure of the molded interfitting sleeves and other aspects of construction.
A drawback of prior devices has been the complicated nature of the drive means requiring precise shaping of pairs of interfitting threads on the sleeves. Another drawback has been the relatively complicated operation necessary to rotatably join the casing and base.